Observations of $\Lambda_b^0 \to \Lambda K^+\pi^-$ and $\Lambda_b^0 \to \Lambda K^+K^-$ decays and searches for other $\Lambda_b^0$ and $\Xi_b^0$ decays to $\Lambda h^+h^{\prime -}$ final states

TL;DR

This paper reports the first observation of certain charmless three-body decays of the Lambda_b^0 baryon, measures their properties, and searches for similar decays in Xi_b^0, using LHCb data.

Contribution

It presents the first observation and measurement of specific Lambda_b^0 decays and sets limits on Xi_b^0 decay modes, expanding knowledge of baryon decay processes.

Findings

First observation of Lambda_b^0 -> Lambda K+ pi- and Lambda_b^0 -> Lambda K+ K- decays

Evidence for Lambda_b^0 -> Lambda pi+ pi- decay

Limits on Xi_b^0 decays to Lambda h+ h'- final states

Abstract

A search is performed for the charmless three-body decays of the $\Lambda_b^0$ and $\Xi_b^0$ baryons to the final states $\Lambda h^+h^{\prime -}$, where $h^{(\prime)} = \pi$ or $K$. The analysis is based on a data sample, corresponding to an integrated luminosity of $3 \rm fb^{-1}$ of $pp$ collisions, collected by the LHCb experiment. The $\Lambda_b^0 \to \Lambda K^+\pi^-$ and $\Lambda_b^0 \to \Lambda K^+K^-$ decays are observed for the first time and their branching fractions and $CP$ asymmetry parameters are measured. Evidence is seen for the $\Lambda_b^0 \to \Lambda \pi^+\pi^-$ decay and limits are set on the branching fractions of $\Xi_b^0$ baryon decays to the $\Lambda h^+h^{\prime -}$ final states.